Preparation method of acylbenzenes

Abstract

A process for the production of acylbenzenes, comprising reacting diacetoxybenzoyl chloride with a Grignard reagent in the presence of an iron-containing catalyst. The acylbenzenes are useful intermediates in a multistep process for the preparation of resveratrol.

The invention claimed is: 
     
       1. A process for the preparation of acylbenzenes represented by the following formula (I): 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a lower-alkyl group with 1-10 carbon atoms, the process comprising reacting diacetoxybenzoyl chloride with a Grignard reagent in the presence of an iron-containing catalyst at a temperature from −70° C. to 40° C., wherein the iron-containing catalyst is selected from the group consisting of iron phthalocyanine chloride, tris(dibenzoylmethanato)iron, tris(hexafluoroacetylacetonato)iron, anhydrous ferric chloride, ferrocene, iron trifluoroacetylacetonate and iron tetraphenylporphine chloride. 
 
     
     
       2. The process of  claim 1 , wherein the Grignard reagent is represented by the formula X—Mg—R, wherein X is Cl, Br or I and R is a lower-alkyl group with 1-10 carbon atoms. 
     
     
       3. The process of  claim 1 , wherein the reaction is carried out at a temperature of from about −40° C. to about 25° C. 
     
     
       4. The process of  claim 1 , wherein the molar ratio of Grignard reagent to the acid chloride is from about 1:10 to about 2:1. 
     
     
       5. The process of  claim 1 , wherein the molar ratio of the iron-containing catalyst to the acid chloride is from about 0.5% to about 10%.